Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jul. 31, 2011	Jul. 31, 2010
Cash flows from operating activities:
Net income	$ 7,393	$ 2,248
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	13,479	10,970
Stock-based compensation	937	770
Gain from bargain purchase in business combination		(1,304)
Provisions for doubtful accounts		797
Provision for inventory obsolescence	63	104
Gross profit from sale of lease pool equipment	(457)	(273)
Excess tax benefit from exercise of non-qualified stock options and restricted shares	(394)	(3)
Deferred tax benefit	(109)	(1,258)
Changes in non-current income taxes payable	694	281
Changes in working capital items, net of effects from business combination:
Accounts receivable	(2,753)	1,225
Contracts receivable	1,718	1,363
Inventories	(565)	1,353
Prepaid expenses and other current assets	(1,119)	(196)
Income taxes receivable and payable	(1,272)	550
Accounts payable, accrued expenses, other current liabilities and deferred revenue	2,023	1,516
Net cash provided by operating activities	19,638	18,143
Cash flows from investing activities:
Purchases of seismic equipment held for lease	(30,461)	(6,957)
Purchases of property and equipment	(253)	(80)
Sale of used lease pool equipment	661	522
Payment for earn-out provision (Note 3)	(155)
Acquisition of AES, net of cash acquired		(2,100)
Net cash used in investing activities	(30,208)	(8,615)
Cash flows from financing activities:
Net payments on line of credit	(20,900)	(6,050)
Proceeds from equipment notes	37
Payments on borrowings	(2,000)	(120)
Net purchases of short-term investments	(101)	(52)
Proceeds from issuance of common stock upon exercise of options	739	244
Net proceeds from public offering of common stock (Note 8)	30,994
Excess tax benefit from exercise of non-qualified stock options and restricted shares	394	3
Net cash provided by (used in) financing activities	9,163	(5,975)
Effect of changes in foreign exchange rates on cash and cash equivalents	657	83
Net change in cash and cash equivalents	(750)	3,636
Cash and cash equivalents, beginning of period	14,647	6,130
Cash and cash equivalents, end of period	13,897	9,766
Supplemental cash flow information:
Interest paid	497	314
Income taxes paid	3,529	1,220
Purchases of seismic equipment held for lease in accounts payable at end of period	$ 7,524	$ 10,010